package practice;

// 使用两个线程来累加 count 的值
// 每个线程循环 1w 次，累加变量 count 的值，count 默认值为 0，注意线程安全问题

public class CountSum {

    static class Counter {
        public static int count = 0;

        // 保证原子性
        public synchronized void increase() {
            count++;
        }
    }

    public static void main(String[] args) throws InterruptedException {
        Counter counter = new Counter();
        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 1_0000; i++) {
                counter.increase();
            }
        });

        Thread t2 = new Thread() {
            @Override
            public void run() {
                for (int i = 0; i < 1_0000; i++) {
                    counter.increase();
                }
            }
        };

        t1.start();
        t2.start();

        // 保证俩线程运行完
        t1.join();
        t2.join();

        System.out.println("count: " + counter.count);
    }
}
